A Limit on the Number of Isolated Neutron Stars Detected in theROSATBright Source Catalogue
Author(s) -
Robert E. Rutledge,
D. B. Fox,
M. Bogosavljević,
A. Mahabal
Publication year - 2003
Publication title -
the astrophysical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.376
H-Index - 489
eISSN - 1538-4357
pISSN - 0004-637X
DOI - 10.1086/378040
Subject(s) - rosat , physics , astrophysics , neutron star , sky , galaxy , limit (mathematics) , radius , stars , astronomy , computer science , mathematics , mathematical analysis , computer security
The challenge in searching for non-radio-pulsing isolated neutron stars(INSs) is in excluding association with objects in the very large error boxes(~13", 1 sigma radius) typical of sources from the largest X-ray all-skysurvey, the ROSAT All-Sky-Survey/Bright Source Catalog (RASS/BSC). We searchfor candidate INSs using statistical analysis of optical (USNO-A2), infrared(IRAS), and radio (NVSS) sources near the ROSAT X-ray localization, and showthat this selection would find 20% of the INSs in the RASS/BSC. This selectionfinds 32 candidates at declinations greater than -39 deg, among which are twopreviously known INSs, seventeen sources which we show are not INSs, andthirteen the classification of which are as yet undetermined. These resultsrequire a limit of <67 INSs (90% confidence, full sky, assuming isotropy) inthe RASS/BSC. This limit modestly constrains a naive and optimistic model forcooling NSs in the galaxy.Comment: ApJ, submitte
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